Cheese's Long Life: The Science Behind Its Shelf Stability

Cheese is a dairy product with a long shelf life, but this varies depending on the type of cheese. Hard cheeses like Cheddar, Parmesan, and Gouda have a lower moisture content, which helps extend their shelf life. On the other hand, soft cheeses such as Brie and Camembert have a shorter shelf life due to their higher moisture content. Proper storage methods, such as wrapping cheese in parchment paper or storing it in the right part of the fridge, can also impact how long cheese lasts.

Hard cheeses have a lower moisture content, which helps extend their shelf life

Hard cheeses, such as Cheddar, Parmesan and Gouda, have a lower moisture content, which helps extend their shelf life. This is because moisture is needed for bacterial growth, so cheeses with higher moisture levels have a shorter shelf life. Harder cheeses with lower moisture levels will last longer, as they lack the ideal environment for bacteria to thrive.

Hard cheeses that haven't been opened can last for several months and even up to a year when stored in the fridge. Once opened, a package of hard cheese can last a long time—about four weeks in the refrigerator. Unopened packages will last about six months, per the experts at the USDA.

Hard cheeses can also be left out of the refrigerator for longer than soft cheeses. The U.S. Department of Health doesn’t recommend keeping any perishable food sitting out of the fridge for more than two hours. Soft cheeses, like cottage or cream cheese, brie, or fresh mozzarella, have a higher moisture content and are not aged, making them much more perishable and susceptible to bacteria or spoilage. Harder cheeses, on the other hand, can be left out for up to four hours, according to the Dairy Farmers of Wisconsin.

Hard cheeses are also less likely to go bad in the traditional sense, but they might grow some mould or dry out. If the outside of the cheese is dry or mouldy, it can be trimmed off, and the cheese underneath will have a better texture. This process is called "facing" and is common in the professional cheese world.

Soft cheeses have a higher moisture content, making them more perishable

Soft cheeses, such as ricotta, feta, mozzarella, and cream cheese, have a high moisture content, which makes them more perishable than harder cheeses. The more water left in the cheese, the more perishable it is. Soft cheeses are also highly susceptible to bacterial growth, which means they are more likely to spoil and have a shorter shelf life.

Fresh cheeses like cream cheese, ricotta, and cottage cheese are highly perishable and usually last only a few weeks past their 'best by' date when stored in the refrigerator. Soft cheeses like Brie, goat's cheese, mozzarella, and feta are more perishable and typically last for a week to a few weeks in the refrigerator. Opened soft cheeses should be consumed within a week or two of opening.

The shelf life of soft cheese is so short that proper storage is key for getting the most out of the product. For cheese sold in brine, like feta or fresh mozzarella, keep it in the liquid and make sure the container's lid is secure. For blue cheese, it can be stored in aluminium foil. Soft-ripened cheese like Brie has a delicate rind, so it needs more care than other soft cheeses. It can be wrapped in cheese paper or parchment paper and kept in an airtight container.

Semi-hard cheeses, such as cheddar, Gruyère, Comté, aged Manchego, and Monterey Jack, contain less moisture than soft cheese. With less moisture, they have a slightly longer shelf life of two to three weeks in the fridge.

Proper storage methods can dramatically extend the shelf life of cheese

The key to proper cheese storage is to allow the cheese to "breathe" while also protecting it from the low humidity in the fridge. Wrapping cheese too tightly can suffocate it, reducing its quality and flavour and encouraging the growth of unwanted bacteria. Instead, cheese should be wrapped gently in parchment paper, butcher paper, wax paper, cheese paper, or cheesecloth before being placed in the fridge. For soft and semi-soft cheeses, it is best to store them in their natural liquid in a plastic container.

It is also important to note the type of cheese when considering storage methods. Hard cheeses, such as Cheddar, Parmesan, and Gruyere, have a lower moisture content, which helps extend their shelf life. These cheeses can be stored in an airtight container or wrapped tightly in the coldest part of the fridge. On the other hand, soft cheeses, such as Brie, goat's cheese, mozzarella, and feta, are more perishable and typically last for only a week to a few weeks in the refrigerator. Fresh cheeses like cream cheese, ricotta, and cottage cheese are highly perishable and usually last only a few weeks.

Additionally, it is recommended to buy smaller amounts of cheese more frequently to ensure freshness. When storing cheese in the refrigerator, it is best to do one big piece per variety rather than a few smaller pieces of each. This will maximise the cheese's chance of survival.

Different cheeses have different shelf lives

The shelf life of cheese depends on its moisture content. Moisture is necessary for bacterial growth, so cheeses with higher moisture levels spoil more quickly. In contrast, cheeses with lower moisture levels last longer because they lack the ideal environment for bacteria to thrive.

Hard cheeses like Cheddar, Parmesan, and Gouda have a lower moisture content, which helps extend their shelf life. Unopened, they can last for several months or even a year when stored in the fridge. Once opened, hard cheeses can last a few weeks to a couple of months.

Semi-hard cheeses like Swiss cheese and cheddar have a slightly longer shelf life than soft cheeses, often several months past their 'best by' date when kept in the refrigerator before opening. Once opened, they will last two to three weeks in the fridge.

Soft cheeses such as Brie, Camembert, and feta have a shorter shelf life. Unopened, they typically last for a few weeks to a couple of months past their 'best by' date when refrigerated. Once opened, soft cheeses should last about a week in the fridge.

Fresh cheeses like cream cheese, ricotta, and cottage cheese are highly perishable and usually last only a few weeks past their 'best by' date when stored in the refrigerator.

It's important to note that the shelf life of cheese can be extended by proper storage. Cheese should be wrapped in parchment paper, cheesecloth, butcher paper, cheese storage bags, or beeswax wrap and stored in the coldest part of the fridge.

Expiration dates are not always accurate for cheese

However, the shelf life of cheese depends on more than just its texture. The storage method also plays a crucial role. Proper storage can dramatically extend the life of cheese in the refrigerator. Cheese should be wrapped in parchment, wax, or cheese paper, which allows it to breathe and release moisture, while protecting it from low humidity. Plastic wrap is not ideal as it can dry out the cheese and impart an unpleasant flavour. Additionally, the cheese should be stored in an airtight container and kept in the coldest part of the fridge to maximise its shelf life.

Furthermore, expiration dates on cheese are often guidelines for quality rather than safety. Cheese often remains safe to consume beyond its "best-by" or "sell-by" dates, provided it is stored correctly. While soft cheeses are more susceptible to spoilage and should be discarded if mould is present, hard cheeses can simply be trimmed to remove any mouldy parts. Other signs of spoilage include unpleasant odours, changes in texture, discolouration, and an off or sour taste.

Therefore, when determining whether cheese has expired, it is essential to consider factors beyond the expiration date. The type of cheese, storage method, and signs of spoilage all play a role in determining its shelf life.

Frequently asked questions